Apply It: Dilute your drink

From the field: The American College of Sports Medicine says, “Sports beverages for use during prolonged exercise should generally contain 4–8 percent carbohydrate,” but Lim believes that range extends much too high. He found the Team Garmin cyclists were best able to stay hydrated and fueled when drinking a 4 percent carbohydrate solution. Anything above that, he found, led to slower absorption and gut cramping. That means no more than 90 calories in a 20-ounce water bottle.

From the lab: Gatorade Sports Science Institute director Xiaocai Shi, Ph.D., reviewed five decades’ worth of sports drink research and concluded that “CHO (carbohydrate) concentration is negatively related to water absorption,” particularly above an 8 percent carbohydrate solution, or 180 calories per 20 ounces of water. That means a drink with low carbohydrate concentration can be absorbed more quickly than one with more carbs, corroborating Lim’s concept but stating a much higher limit than Lim recommends.

Do it: Measure out 90 calories’ worth of your favorite drink powder and mix it with 20 ounces of water. If you prefer a pre-mixed sports drink, estimate the volume that contains 90 calories of carbohydrate and top off with water.

Dr. Gatorade’s Take

Robert Murray, Ph.D., director of the Gatorade Sports Science Institute from 1985-2008 agrees with some of Lim’s and Sims’ ideas, but not all. The experienced sports nutrition scientist weighs in on the tenets of this new refueling strategy.

Dilute the drink: Disagree

Murray’s research and experience shows that drinks with Lim’s suggested 4 percent carbohydrate solution are not absorbed faster than more concentrated versions. “Sports drinks containing up to 6–7 percent carbohydrate (130-150 calories per 20 ounces) empty from the stomach and are absorbed at similar rates, so there’s no absorption advantage to diluting sports drinks,” he says.